High electric current density-induced interfacial reactions in micro ball grid array (μBGA) solder joints

The effect of a high electric current density on the interfacial reactions of micro ball grid array solder joints was studied at room temperature and at 150 °C. Four types of phenomena were reported. Along with electromigration-induced interfacial intermetallic compound (IMC) formation, dissolution at the Cu under bump metallization (UBM)/bond pad was also noticed. With a detailed investigation, it was found that the narrow and thin metallization at the component side produced “Joule heating” due to its higher resistance, which in turn was responsible for the rapid dissolution of the Cu UBM/bond pad near to the Cu trace. During an “electromigration test” of a solder joint, the heat generation due to Joule heating and the heat dissipation from the package should be considered carefully. When the heat dissipation fails to compete with the Joule heating, the solder joint melts and molten solder accelerates the interfacial reactions in the solder joint. The presence of a liquid phase was demonstrated from microstructural evidence of solder joints after different current stressing (ranging from 0.3 to 2 A) as well as an in situ observation. Electromigration-induced liquid state diffusion of Cu was found to be responsible for the higher growth rate of the IMC on the anode side.

[1]  K. Tu,et al.  Tin–lead (SnPb) solder reaction in flip chip technology , 2001 .

[2]  Sinn-wen Chen,et al.  Electromigration effects upon interfacial reactions , 2003 .

[3]  King-Ning Tu,et al.  Mean-time-to-failure study of flip chip solder joints on Cu/Ni(V)/Al thin-film under-bump-metallization , 2003 .

[4]  Sinn-wen Chen,et al.  Electromigration effect upon the Sn/Ag and Sn/Ni interfacial reactions at various temperatures , 2002 .

[5]  Zuhair A. Munir,et al.  Electromigration effects in Al-Au multilayers , 2001 .

[6]  S. Nakahara,et al.  Room temperature interdiffusion studies of Au/Sn thin film couples , 1981 .

[7]  King-Ning Tu,et al.  Electromigration failure in flip chip solder joints due to rapid dissolution of copper , 2003 .

[8]  Sinn-wen Chen,et al.  Effects upon interfacial reactions by electric currents of reversing directions , 2003 .

[9]  Sinn-wen Chen,et al.  Electromigration effects upon the low-temperature Sn/Ni interfacial reactions , 2003 .

[10]  Karl J. Puttlitz,et al.  Area array interconnection handbook , 2001 .

[11]  M. Fine,et al.  Thickening kinetics of interfacial Cu6Sn5 and Cu3Sn layers during reaction of liquid tin with solid copper , 2003 .

[12]  Y. C. Chan,et al.  Reliability study of the electroless Ni-P layer against solder alloy , 2002, Microelectron. Reliab..

[13]  Y. Chan,et al.  Effect of reaction time and P content on mechanical strength of the interface formed between eutectic Sn–Ag solder and Au/electroless Ni(P)/Cu bond pad , 2003 .

[14]  Sinn-wen Chen,et al.  Electromigration effect upon the Sn–0.7 wt% Cu/Ni and Sn–3.5 wt% Ag/Ni interfacial reactions , 2001 .

[15]  Fu Guo,et al.  Mechanical properties of intermetallic compounds associated with Pb-free solder joints using nanoindentation , 2003 .

[16]  K. Tu,et al.  Microstructure-electromigration correlation in a thin stripe of eutectic SnPb solder stressed between Cu electrodes , 1999 .

[17]  Hua Ye,et al.  Thermomigration in Pb–Sn solder joints under joule heating during electric current stressing , 2003 .

[18]  H. Conrad.  Effects of electric current on solid state phase transformations in metals , 2000 .

[19]  Z. A. Munir,et al.  Enhanced growth of intermetallic phases in the Ni–Ti system by current effects , 2003 .

[20]  Sinn-wen Chen,et al.  Electric current effects upon the Sn/Cu and Sn/Ni interfacial reactions , 1998 .

[21]  J. O. Suh,et al.  Mechanism of electromigration-induced failure in the 97Pb-3Sn and 37Pb-63Sn composite solder joints , 2003 .

[22]  Sinn-wen Chen,et al.  Electric current effects on Sn/Ag interfacial reactions , 1999 .

[23]  Y. C. Chan,et al.  Interfacial reaction of Pb-Sn solder and Sn-Ag solder with electroless Ni deposit during reflow , 2002 .

[24]  Sinn-wen Chen,et al.  Electromigration effect upon the Zn/Ni and Bi/Ni interfacial reactions , 2000 .

[25]  King-Ning Tu,et al.  Current-crowding-induced electromigration failure in flip chip solder joints , 2002 .

[26]  K. Tu.  Recent advances on electromigration in very-large-scale-integration of interconnects , 2003 .